Woven bracing for intermodal transport

ABSTRACT

A load bracing system and method for securing cargo within a transport container such as intermodal containers which incorporates woven polyethylene load restraining strips and load shifting devices such as dunnage bags. The load restraining strips are adapted to be banded around an unconfined end of the cargo while the load shifting devices are intended to shift the loads to induce tension in the load restraining strips, thereby securely restraining the cargo.

BACKGROUND OF THE INVENTIONS

The inventions described and claimed herein relate generally to cargo restraint systems for transport containers, such as truck trailers, intermodal containers, and railroad flatcars. Specifically, one embodiment of the load bracing system comprises woven, adhesive backed, flexible bracing and one or more expansion devices, such as an dunnage air bag, and a method for using such load bracing system.

It is well known that loads in transport containers are subject to extreme forces during transport, whether the loads are being transported by rail, by sea or by land. These forces can cause severe damage to the contained goods, and even worse, to the environment if hazardous goods are being transported, if the loads are not adequately secured in the container. The problems inherent in transporting cargo are well discussed in the prior art, including U.S. Pat. Nos. 4,264,251; 6,089,802; 6,227,779; and 6,896,459, which are incorporated herein by reference.

A prior art load restraint system designed to solve these problems is disclosed in U.S. Pat. No. 6,227,779 (the '779 patent). The restraint system in the '779 patent utilizes three strips of polyester substrate material and a tensioning tool (clothespin). Essentially, the securement method disclosed in the '779 patent calls for the ends of two of the strips to be secured to opposite sidewalls of the containers while the free ends are wrapped around the unconfined end of the load to be restrained. At that point, the two free ends of the two strips are adhered together, after which the tensioning tool, having two fingers, is engaged with the overlapping strips, one finger on each side of the overlapping strips. The tool is then manually rotated with a wrench, causing the overlapping strips to roll up around the tensioning tool. Once the restraining strips are drawn taut, the third strip of polyester material is placed across the joint formed near the tensioning tool to secure the load and to prevent the rolled up portion from unrolling.

While the prior art system described in the '779 patent may be successful in securing loads in transport containers, the system does have its drawbacks. For instance, the method described is believed to be time consuming and require significant manual labor to induce tension in the strips. Furthermore, it is believed that the ratcheting method tends to pull the load restraining strips away from the container sidewalls, weakening the adhesive connection. Even further, the material called for in the '779 patent is believed to have relatively low tensile strength and relatively high elongation, as compared to the material disclosed herein. As discussed at column 5, lines 48-63 of the '779 patent, the polyester material is preferably a film of spun bonded olefin.

SUMMARY OF THE INVENTIONS

Although there are some similarities between the devices and methods disclosed herein and the prior art, there are also some very significant and novel differences. For instance, while the prior art systems use spun bonded material for the load restraint strips, disclosed herein is a woven fabric, made of a material such as polyethylene or other polymeric material, have low elongation and high tensile strength. First, spun bonded materials can be expensive, while woven materials are believed to cost less. Second, spun bonded materials generally have relatively high elongation, and as such cannot effectively restrain cargo unless the material is drawn taut by ratcheting. Spun bonded materials stretch too much and would allow an unacceptable amount of load shifting without ratcheting. In contrast, woven materials generally have lower elongation (i.e., are more stiff) and thus can work effectively in this application without drawing the material taut. Third, pound for pound, woven materials are believed to be stronger that spun bonded materials. In that respect, less material need be used for a given load.

Rather than using the “ratcheting” method of the prior art, whereby slack in the load restraining strips is wound up, the devices and methods disclosed herein utilizes load shifting devices which expand, such as dunnage air bags, to move the transported loads into tight contact with the load restraining strips. In the devices and methods disclosed herein, after the cargo has been loaded into the container and the load restraining strips overlapped around the unconfined end of the cargo, a dunnage bag is preferably placed between two adjacent loads directly behind the two connected strips. The dunnage bag is then inflated using compressed air which shifts the load outward towards the container sidewalls. This movement has the effect of inducing tension in the load restraining strips. Once pre-tensioned in this manner, the load restraining strips stretch less for a given force and thus provide a more secure restraint for the cargo.

As discussed above, the tensioning of the load restraining strips of the prior art is believed to have the tendency to weaken the adhesive connection at the container sidewall. Contrary to the prior art, it is believed that the restraint method and system disclosed herein has the tendency to actually strengthen the adhesive connection at the container sidewall. The dunnage bag of the devices and methods disclosed herein forces the cargo outward towards the container sidewalls. As such, the cargo loads press against the load restraining strips at their point of connection to the container sidewalls. This is believed to make the adhesive adhere better, resulting in a much stronger restraint system.

It is also believed that the methods of restraining cargo disclosed herein are faster and requires less manual labor that the prior art. While the prior art systems are believed to require much time and labor to ratchet up the slack in the load restraining strips, the devices and methods disclosed herein allow dunnage bags to be dropped in place and inflated very quickly and easily.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, objects, and advantages of the inventions described and claimed herein will become better understood upon consideration of the following detailed description, appended claims, and accompanying drawings where:

FIG. 1 is a perspective view showing the interior of a container, such as a truck trailer, in which is illustrated the installation and use of a novel and inventive barrier system;

FIG. 2 is a plan view showing the interior of the container in which is illustrated the installation and use of the barrier system just prior to inflation of an expansion device; and,

FIG. 3 is a plan view showing the interior of a container in which is illustrated the installation and use of the barrier system just after inflation of the expansion device.

It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the inventions described and claimed herein or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the inventions described herein are not necessarily limited to the particular embodiments illustrated herein.

Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following description of the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring first to FIG. 1, an embodiment of the barrier system disclosed herein is illustrated restraining cargo (or loads) 20 in the interior of a container 10. Although the container 10 depicted in FIG. 1 is a truck trailer, the invention is in no way intended to be limited to such application. Indeed, the devices and methods disclosed herein are intended for use in many other types of containers, such as rail cars and intermodal transport containers.

The barrier system disclosed herein is preferably comprised of three load restraining strips 30, 40 and 50 and an expansion device 60. As depicted in FIG. 1, the first ends of the first and second load restraining strips 30, 40 are adapted to be attached to opposite interior side walls 12 of the container 10 near an unconfined end of the loads 20 to be restrained. The opposite (or second) ends of the first and second load restraining strips are adapted to be attached to each other across the unconfined end of the loads 20 in close proximity to the loads 20. The third load restraining strip 50 is adapted to be banded across the first and second load retaining strips 30, 40 to provide a more secure attachment between the two.

Once the load restraining straps 30, 40, 50 are fixed in place, the expansion device 60 is intended to be disposed between two adjacent loads 60 directly behind the load restraining strips 30, 40, 50, preferably aligned parallel to the longitudinal axis of the container 10, as depicted best by FIG. 2. Initially, the expansion device 60 is in its unexpanded condition, and as such can be easily placed between adjacent loads 20. Once the expansion device 60 is set in a proper location, the expansion device 60 is expanded which forces the loads 20 outward towards the container sidewalls 12, as depicted in FIG. 3.

The shifting of the loads 20 outward generally serves two purposes. First, since the load restraining strips 30, 40, 50 were originally placed in close proximity to the loads 20, the load shifting induces tension (i.e., pre-tensions) the load restraining strips 30, 40, 50. As it is well known, for most materials, the elongation of a material becomes progressively less the more tension the material is subjected to. Hence, the cargo 20 will be more secure (i.e. will move less when subjected to the same magnitude of force) after the material is pre-tensioned. Second, the expansion device 60 shifts the loads 20 outward preferably into contact with the container sidewalls 12. In that manner, the first ends of the load restraining strips 30, 40 are wedged in between the loads 20 and the container sidewalls 12, which tends to enhance the connection between the load restraining strips 30, 40 and the container sidewalls 12.

The load restraining strips 30, 40, 50 are preferably supplied in roll 70 form, whereby the strips 30, 40, and 50 are cut from the roll 70 using scissors, utility knives or the like. The preferable roll 70 has dimensions of approximately fourteen inches wide by three hundred and fifty feet long, and the length of the material is preferably continuous with no perforations of any kind. However, the dimensions and structure of the roll 70 can vary depending upon a number of factors including the size and weight of the load 20 to be restrained.

As depicted in FIG. 4, the strips 30, 40, and 50 are preferably comprised of four material layers. The layer 72, is a woven fabric layer, although any material which has low elongation and high tensile strength would probably suffice. The woven fabric layer 72 is preferably woven polyethylene having a density of approximately 120 g/m². The preferred fabric layer is manufactured by Changzhou Ssangleong Industrial Textile Co. Ltd. The fabric layer 72 can be woven on either a circular or flat loom.

The layer 74 is preferably an adhesive coating with a surface density of approximately 125 g/m². The preferred adhesive is manufactured by Changzhou Jianyou Sanitation Datum Co., ltd, although other types of adhesive will suffice so long as such adhesive has enough tack to adhere the strips 30, 40 to either an interior wall of an over-land trailer or ocean container. The adhesive layer preferably has the same dimensions as the entire roll (i.e., 14 inches wide by 350 feet long)

The layer 76 can be best characterized as a release liner. The preferred release liner 76 may be made of any suitable material so long as the it will adhere to the adhesive layer 74, but may easily be removed from the adhesive. Preferably, the release liner has a surface density of approximately 60-80 g/m² and has the same continuous length as the roll of material (i.e., 350 feet). However, the width of the preferred release liner 76 is approximately 14.5 inches or 0.5 inch wider than the width of the fabric and adhesive layers 72, 74. Hence, the release liner 76 overhangs the width of the fabric and adhesive layers 72, 74 by 0.25 inch at both edges of the roll 70, to allow the release liner 76 to be easily peeled.

The layer 78 is preferably a polypropylene coating having a surface density of approximately 30 g/m². This coating 78, which preferably has the same continuous dimensions as the entire roll 70 (i.e., 14 inches wide by 350 feet long) allows printing to be applied to the outer surfaces of the fabric. To enable a user to accurately cut the material to a desired length, the outer surface of layer 78 is preferably printed with hash marks every 1 foot. In addition to the hash marks, which assist in use of the fabric, the printable surface may also contain other information such as instructions or manufacturer information such as trademarks and other information in the nature of advertising, and the like.

The expansion device 60 is preferably an dunnage air bag, although other similar bracing or blocking devices may be adequate. Dunnage air bags 60 are usually paper bags constructed of several layers of paper and include an inflatable internal bladder which can be inflated with compressed air. Dunnage air bags 60 are traditionally used to restrain movement of cargo loads in containers. They 60 are generally used to fill voids, brace loads, absorb vibrations and protect cargo from in-transit damage. In the devices and methods disclosed herein, as discussed above, the dunnage air bag 60 is used as a load shifting device to pre-tension the load restraining strips. The size and strength of the dunnage air bags will depending upon the size and weight of the cargo 20.

Dunnage air bags 60 generally are not capable of shifting loads 20 very far. However, the nature of the preferred material for the strips 30, 40, 50 does not require the load 60 to be shifted very far. As discussed above, the preferred material for the strips 30, 40 50 is a low stretch material, and as such does not need to be stretched very far to induce a sufficient amount of tension. Although the woven material is ideal for use in this system, because of its low elongation, it is contemplated that the prior art spun bonded materials could be used in conjunction with the dunnage air bags 60. However, if it were, it is likely that a greater number of dunnage bags may be required to shift the loads a greater distance.

One method of using the system of the barrier system disclosed herein, as follows, is a method of use for loads (either non-hazardous or hazardous) that are transported over land or over sea in intermodal trailers or containers and for non-hazardous loads transported via container on the rail:

-   -   1. Remove roll 70 from packaging.     -   2. Using a utility knife or similar cutting instrument, cut two         twelve foot strips 30, 40 from the roll 70.     -   3. From either end of the strips 30, 40, peel back a six foot         length of the release liner 76.         -   a. The six feet of release liner 76 can either be removed             with the cutting instrument or left hanging.     -   4. Beginning two feet behind one of the two horizontally         adjacent pallets 20 that the strips 30, 40 will be securing,         apply the exposed six foot strip 30 with the adhesive side 74         against the wall 12 of the intermodal trailer or container 10.         -   a. Apply the strip 30 horizontally along the wall and level.         -   b. Apply the strip 30 a minimum of four inches above the top             deck of the pallet 20 you are securing.         -   c. Use hand pressure to allow the adhesive 74 to adhere to             the wall 12.         -   d. Then use a rolling device to insure full contact has been             made to the wall.     -   5. Repeat step 3 with the second strip 40 on the opposite wall         in the same location.     -   6. Repeat step 4 with the second strip 40.     -   7. Either of the remaining six foot unattached segments of         strips 30, 40 can now be the interior strip.     -   8. After choosing the interior strip 30, peel away the remaining         ten feet of release liner 76. The remaining strip shall be the         outer strip 40.     -   9. Pull the interior band 30 snuggly around the front of the         load 20.     -   10. Take the outer strip 40 snuggly around the front of the load         20 and place on top of the interior strip 30 at the front of the         load 20.         -   a. Press the outer strip 40 against the adhesive 74 of the             interior strip 30.             -   i. This will be the side of the outer strip 30 that does                 not have an adhesive layer 74, thus the peel away                 release liner 76 will be facing out from the front of                 the load 20 being secured;             -   ii. Use hand pressure to allow contact of the adhesive                 of the interior strip 30 to the material of the outer                 strip 40.     -   11. Peel away remaining release liner from the exposed outer         strip 40.     -   12. Using a utility knife or similar cutting instrument, cut an         eight foot strip 50 of material from the roll 70;     -   13. Peel away the entire release liner 76 from the strip 50     -   14. Place the eight foot strip 50 with the adhesive 74 side on         top of the exposed outer strip 40 and exposed portion of the         inner strip 30, making sure to bridge the two strips with the         eight foot strip.         -   a. Use hand pressure to adhere the adhesive 74 of the outer             strip 40 to the adhesive 74 of the eight foot strip 50.         -   b. This adhesive to adhesive contact allows for added             security to brace the load 20.     -   15. Place an air bag 60 or similar blocking and bracing device         vertically between the two adjacent loads 20 directly behind the         two connected strips 30, 40         -   a. If an air bag is used, inflate the air bag     -   16. For additional security, one (or more) strips cut from the         roll 70 may be used per individual load 20 placed vertically on         the load         -   a. Measure height of the load 20 eight inches beyond the top             of the load to top decking of pallet 20.         -   b. Using a utility knife or similar cutting instrument, cut             strips from the roll 70.         -   c. Peel away the entire release liner 76 from the strips.         -   d. At the approximate center point of either adjacent load,             using hand pressure, attach the exposed adhesive 74 side of             the strips beginning eight inches above the top of the load             to the top deck of the pallet         -   e. Repeat steps 16 a-d for the adjacent load.

The following is another method of use when transporting hazardous loads over rail via container:

-   -   1. Remove roll from packaging.     -   2. Using utility knife or similar cutting instrument (please         wear proper safety gloves) cut 2 bands thirteen feet in length         from the roll.     -   3. From either end of one of the thirteen foot bands, peel back         six feet of the peel away backing;         -   a. The six feet of backing can either be removed with a             cutting instrument or left hanging.     -   4. Beginning two feet behind one of the two horizontally         adjacent pallets that the fabric will be securing, apply the         exposed six feet of the fabric with the adhesive side against         the wall of the container that is to be placed on the chassis to         be used on the rail.         -   a. Apply the band of fabric horizontally along the wall and             level.         -   b. Apply the band a minimum of four inches above the top             deck of pallet you are securing.         -   c. Use hand pressure to allow the adhesive to adhere to the             wall         -   d. Then use a rolling device to insure full contact has been             made to wall     -   5. Repeat step 3 with the second thirteen foot band of fabric on         the opposite wall in the same location.     -   6. Repeat step 4 with the second thirteen foot band of fabric;     -   7. Either of the remaining seven feet unattached segments of the         fabric can now be the interior band.     -   8. After choosing the interior band, peel away the remaining         seven feet of peel-away backing from that band. The remaining         band will be the outer band.     -   9. Pull the interior band around the front of the load that you         are securing, leaving some slack.     -   10. Take the outer band around the front of the load you are         securing and place on top of the interior band at the front of         the load you are securing.         -   a. Press the outer band against the adhesive of the interior             band.             -   i. This will be the side of the outer band that does not                 have adhesive thus the peel away backing will be facing                 out from the front of load being secured.             -   ii. Use hand pressure to allow contact of the adhesive                 of the interior band to the material of the outer band.     -   11. Peel away the backing of the outer band;         -   b. Use utility knife or similar cutting instrument, and             proper safety gloves, to cut away backing if needed.     -   12. Cut a four inch piece of fabric. Peel away backing and         adhere just right of center (facing load) of load with adhesive         side adhering to band. Place the tongs of the tensioning tool on         right edge of the four inch piece.     -   13. Using tensioning tool tighten the inner and outer bands         together making sure to turn clockwise. When secure, leave         tensioning tool in place.     -   14. Using utility knife or similar cutting instrument, cut one         eight-foot band of fabric from a roll of fabric.     -   15. Peel away entire backing from the eight-foot band.     -   16. Place the eight-foot band of fabric with adhesive side on         top of entire exposed potion of the outer band.         -   a. Use hand pressure to adhere adhesive of outer band to             adhesive of eight-foot band of fabric.         -   b. This adhesive to adhesive contact allows for added             security to brace the load.     -   17. Remove tension tool. It should slide out easily     -   18. For additional security, one band of fabric may be used per         individual load placed vertically on the load.         -   a. Measure height of load eight inches beyond top of load to             top decking of pallet.         -   b. Using utility knife or similar cutting instrument and             wearing proper safety gloves, cut two bands of fabric to             measurement acquired in 18 a above.         -   c. Peel away the entire backing of that band.         -   d. At the approximate center point of either adjacent load,             using hand pressure, attach the exposed adhesive side of the             fabric beginning eight inches above the top of the load to             the top deck of the pallet     -   19. Repeat 18 a-d for the adjacent load.

Although the inventions described and claimed herein have been described in considerable detail with reference to certain exemplary embodiments, one skilled in the art will appreciate that the inventions described and claimed herein can be practiced by other than these embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments contained herein. 

1. A system for bracing loads within an intermodal container during transport, the system comprising: a first, a second, and a third load restraining strip, and at least one expansion device; the first, second, and third load restraining strips being comprised of woven polyethylene fabric having an adhesive applied upon one surface thereof and a release liner covering the adhesive; the first and second restraining strips each having a first and a second end and being operable at the first end to adhere to opposite interior sidewall surfaces of the intermodal container and at the second end to extend at least partially across an unconfined end of the loads to be restrained; the first and second restraining strips being operable to adhere together around the unconfined end of the loads and to be banded together using the third restraining strip; and, the at least one expansion device being adapted to be disposed at a location selected from the group consisting of between two adjacent loads and between a load and an adjacent sidewall of the container, the at least one expansion device being adapted to shift loads to induce tension in the first, second, and third restraining strips.
 2. A system for bracing loads within a container, the system comprising: a first and a second load restraining strip, each having a first and a second end, and at least one expansion device; the first and second load restraining strips being operable at the first end to attach to opposite interior sidewalls of the container; the second end of the first load restraining strip being operable to attach to the second end of the second load restraining strip such that the first and second load restraining strips extend across an unconfined end of the loads to be restrained; the at least one expansion device being adapted to be disposed at a location selected from the group consisting of between two adjacent loads and between a load and an adjacent sidewall of the container; the at least one expansion device being adapted to shift loads to induce tension in the first and second load restraining strips.
 3. The system of claim 2 wherein the first and second load restraining strips are comprised of woven fabric.
 4. The system of claim 3 wherein the woven fabric is characterized by low elongation.
 5. The system of claim 3 wherein the woven fabric is woven polyethylene.
 6. The system of claim 5 wherein the woven polyethylene has a density of approximately 120 g/m².
 7. The system of claim 1 wherein the first and second restraining strips have an adhesive on an inside surface to provide for easy attachment to the sidewalls and to each other.
 8. The system of claim 7 wherein the first and second restraining strips have a printable coating on an outside surface.
 9. The system of claim 7 wherein the first and second restraining strips have printing on an outside surface, the printing being indicative of the length of the strip.
 10. The system of claim 7 wherein the first and second restraining strips are coated with approximately 125 g/m² of the adhesive.
 11. The system of claim 1 wherein the expansion device is an dunnage air bag.
 12. The system of claim 11 wherein the expansion device is disposed between two adjacent loads directly behind the first and second load retaining strips.
 13. The system of claim 12 wherein the dunnage air bag is aligned parallel to the longitudinal axis of the container, whereby inflation of the dunnage air bag forces the loads outward, pushing the first ends of the first and second restraining strips against the container sidewalls.
 14. A method for bracing loads within an intermodal container, the method comprising the steps of: cutting a first, a second, and a third load restraining strip from a roll of woven polyethylene fabric having an adhesive applied upon one surface thereof and a release liner covering the adhesive, the first and second load restraining strips being operable to attachment at a first end to an interior sidewall surface of the intermodal container and at a second end to extend at least partially across an unconfined end of the loads to be restrained; peeling a portion of the release liner from the first end of the first and second load restraining strips; applying the first end of the first and second load restraining strips to opposite interior sidewall surfaces such that the first and second load restraining strips extend across the unconfined end of the loads to be restrained enough to be overlapped; peeling the remaining portion of the release liner from the first load restraining strip; overlapping the second end of the second load restraining strip over the second end of the first load restraining strip such that the second load restraining strip adheres to the first load restraining strip; peeling the remaining portion of the release liner from the second load restraining strip; peeling the release liner from the third load restraining strip; applying the third load restraining strip to an exposed portion of the first and second load restraining strip; placing at least one expansion device at a location selected from a group consisting of between two adjacent loads and between a load and the interior sidewall surface of the intermodal container; and, expanding the at least one expansion device to induce tension in the first and second load restraining strips.
 15. The method of claim 14 wherein the first and second load restraining strips are cut to a length of approximately 16 feet and the third restraining strip is cut to a length of approximately 8 feet.
 16. A method for bracing loads within a container, the method comprising the steps of: cutting a first and a second load restraining strip, the first and second load restraining strips being operable to attachment at a first end to an interior sidewall of the container and at a second end to extend at least partially across an unconfined end of the loads; attaching the first end of the first and second load restraining strips to opposite interior sidewalls such that the first and second load restraining strips extend across the unconfined end of the loads enough to be overlapped; attaching the second end of the second load restraining strip to the second end of the first load restraining strip; placing at least one expansion device at a location selected from a group consisting of between two adjacent loads and between a load and the interior sidewall of the container; and, expanding the at least one expansion device to induce tension in the first and second load restraining strips.
 17. The method of claim 16 further comprising the step of cutting a third load restraining strip and, before placing the at least one expansion device at the location, the step of attaching the third load restraining strip across the first and second load restraining strips.
 18. The method of claim 16 wherein the location is between two adjacent loads directly behind the first and second load restraining strips.
 19. The method of claim 18 wherein the expansion device is an dunnage air bag.
 20. The method of claim 19 wherein the step of expanding the at least one expansion device involves inflating the dunnage bag until the loads on either side of the dunnage air bag firmly contact the container sidewalls, such that the first ends of the first and second load restraining strips are disposed between the loads and the container sidewalls.
 21. The method of claim 16 wherein the first and second load restraining strips are comprised of woven fabric.
 22. The method of claim 21 wherein the woven fabric is characterized by low elongation.
 23. The method of claim 21 wherein the woven fabric is woven polyethylene.
 24. The method of claim 23 wherein the woven polyethylene has a surface density of approximately 120 g/m².
 25. The method of claim 16 wherein the first and second restraining strips have an adhesive coating on one side to provide for easy attachment to the sidewalls and to each other.
 26. The method of claim 25 wherein the steps of attaching the first and second ends of the first and second load restraining strips involves adhering using the adhesive coating.
 27. The system of claim 25 wherein the first and second restraining strips are coated with approximately 125 g/m² of the adhesive. 